Electric annealing hood



Sept. 27,1927. 1,643,600

T. F. BAlLY ELECTRI G ANNEALING HOOD Filed March 18. 1924 f, l f,

' Patented Sept'. 27, 1927.

UNITED STATES THADDEUS F. IBAILY, OF ALLIANCE, OHIO.

ELECTRIC ANNEALING Hoon.

Application led March 18, 1924. Serial No. 700,001.

This invention relates to annealing hoods and more particularly to an electrically heated annealing hood arranged to be placedl over a pack of sheets or the like to be annealed.

The objects of the invention are to provide a stationary pedestal to receive the sheets or other articles to be annealed and a removable hood adapted to be placed over the same and provided with electric resistance elements, a sand seal being provided for forming an air tight joint between the hood and the floor, means being provided for circulating an inert as around the sheets or other articles to e annealed.

The above and other objects may be attained by constructing the annealing hood in the manner'illustrated in the accompanying drawing, in which- Figure 1 is a transverre sectional view through an electric annealing hood embodying the invention, showing the same in operative position; and

Fig. 2, a longitudinal section on the line 2 2, Fig. 1.

Similar numerals refer to similar parts throughout the drawing. i

The floor is indicated at 1 and a pedestal 2, preferably of refractory material, is rigidly mounted upon the floor and extends longitudinally between a pair of spaced side walls 3, which support spaced piers 4 of the same height as the pedestal 2.

Openings 5 are provided in the upper portions of the Walls 3 to permit a passage of air upon each side of the pedestal 2. Longitudinal passages 6 are thus formed between the pede'tal 2 and the side walls 3, which may be connected with the pipes 7 to provide for a circulation of ah inert gas within the annealing hood.

A plate 8 may be supported upon the pedestal 2 and piers 4 for the purpose of supporting a pack of sheets or the like to be annealed, as indicated at 9. A sand trough 10, which may be in the forni of a channel iron as shown, is located in the floor surrounding the pedestal and side walls 3, and

contains sand or the like, as shown at 11.

The hood 12 is provided with the arched refractory lining 13, preferably extended downward and inward at its lower ends as shown at 14, thus providing a central longitudinal opening in the lower portion of the hood of slightly greater width than the pack of sheets to be annealed.

A metal casing 15 may be provided around the exterior of the hood and a supporting arm, such as the channel irons 16, is connected to the under side thereof and arranged to rest upon the floor to support the hood in proper position over the pack.

A flange 17 is also connected to the under side of the hood and arranged to be received in the sand trough 10, in order to-form a :zealed joint at this point to seal the interior ot the hood.

A pair of resistance troughs 18 are provided, one being located near each side wall of the hood, prefer-ably just above the inclined pcrtion 14 therein, being' sup orted upon pi ers 19. Each trough is preferahly of channel shape, as illustrated, and extends the full length of the hood.

The troughs are formed of refractory material .and are filled with a resistance body consisting of a carbonaceous material in granular form, such as crushed coke, charcoal or the like, designated upon the drawing by the numeral 20.

Embedded in the resistance material, preferably near each end of the trough, is an electrode 21, said electrodes extending through the hood as shown in the drawing, and being connected to an electric circuit in the usual manner.

When current is supplied to the electrodes, it will be conducted from one electrode to the other through the resistance material in the trough, thus raising the temperature of the same to the desired degree.

For the purpose of producing an inert gas Within the hood, an oil feed line 22 may be extended through the top of the hood and adapted to drop oil upon the top of the hot pack of sheets, producing a. nonoxidizing gas which may be circulated around the hood in the direction of the arrows shown in Fig. 1, a fan 0r the like being connected to the pipes 7 for the purpose of forming a circulation.

In annealing sheets or the like, the sheets are first placed in a vpack upon the pedestal as shown at 9 in Figs'. 1 and 2, after which the hood is lowered over the sheets in the position shown in the drawings, sealing the 105 interior of the hood.

The resistance elements may be heated to bring the sheets up to the desired tem erature and oil dropped upon the hot s eets from the oil line 22, forming CO which is circulated around the interior of the hood as above described.

l aeaaeoo When the sheets have been annealed and 2. An apparatus of the character described tooled to the desired temperature, the hood including a pedestal to receive material to Ais raised and the sheets may be removed from be annealed and a removable hood adapted l the pedestal. to be placed over the material and pedestal, 15 I claim said hood being of greater Width than the l. A-napparatus o the character described pedestal, the lower open end of the hood including a pedestal to receive material to being restricted and resistor troughs carried be annealed and a removable hood having in the hood above said restricted portion. electric resistor troughs xed therein and In testimony that I claim the above, 'I 20 30 adapted to be'placed over the material and have hereunto subscribed my name.

pedestal. I THADDEUS F. BAILY. 

